Reference : Sex differences in brain aromatase activity: genomic and non-genomic controls
Scientific journals : Article
Social & behavioral sciences, psychology : Neurosciences & behavior
http://hdl.handle.net/2268/101498
Sex differences in brain aromatase activity: genomic and non-genomic controls
English
Balthazart, Jacques mailto [Université de Liège - ULg > Département des sciences biomédicales et précliniques > Biologie de la différenciation sexuelle du cerveau >]
Charlier, Thierry mailto [> >]
Cornil, Charlotte mailto [Université de Liège - ULg > Département des sciences biomédicales et précliniques > Biologie de la différenciation sexuelle du cerveau >]
Dickens, Molly mailto [> >]
Harada, Nobuhiro [> >]
Konkle, Anne T.M. [> >]
Voigt, Cornelia [> >]
Ball, Gregory F. [> >]
2011
Frontiers in Neuroendocrine Science
2
34
Yes
International
[en] Aromatization of testosterone into estradiol in the preoptic area plays a critical role in the
activation of male copulation in quail and in many other vertebrate species. Aromatase
expression in quail and in other birds is higher than in rodents and other mammals, which
has facilitated the study of the controls and functions of this enzyme. Over relatively long
time periods (days to months), brain aromatase activity (AA), and transcription are markedly
(four- to sixfold) increased by genomic actions of sex steroids. Initial work indicated that
the preoptic AA is higher in males than in females and it was hypothesized that this differential
production of estrogen could be a critical factor responsible for the lack of behavioral
activation in females. Subsequent studies revealed, however, that this enzymatic sex difference
might contribute but is not sufficient to explain the sex difference in behavior.
Studies of AA, immunoreactivity, and mRNA concentrations revealed that sex differences
observed when measuring enzymatic activity are not necessarily observed when one measures
mRNA concentrations. Discrepancies potentially reflect post-translational controls of
the enzymatic activity. AA in quail brain homogenates is rapidly inhibited by phosphorylation
processes. Similar rapid inhibitions occur in hypothalamic explants maintained in vitro
and exposed to agents affecting intracellular calcium concentrations or to glutamate agonists.
Rapid changes in AA have also been observed in vivo following sexual interactions
or exposure to short-term restraint stress and these rapid changes in estrogen production
modulate expression of male sexual behaviors. These data suggest that brain estrogens
display most if not all characteristics of neuromodulators if not neurotransmitters. Many
questions remain however concerning the mechanisms controlling these rapid changes in
estrogen production and their behavioral significance.
http://hdl.handle.net/2268/101498
Keywords: aromatase, sex differences, Japanese quail, preoptic area, phosphorylations, immunohistochemistry,
in situ hybridization, non-genomic control

File(s) associated to this reference

Fulltext file(s):

FileCommentaryVersionSizeAccess
Open access
fendo-02-00034.pdfPublisher postprint971.29 kBView/Open

Bookmark and Share SFX Query

All documents in ORBi are protected by a user license.